Rotatable crawler unit for selective longitudinal or sidewise movement



June 26, 1962 TERRELL 3,040,829

ROTATABLE CRAWLER UNIT FOR SELECTIVE LONGITUDINAL OR SIDEWISE MOVEMENT Filed Oct. 18, 1961 5 Sheets-Sheet l INV ENT OR Kahlil/21 101! ATTORNEYS June 26, 1962 R LL 3,040,829

ROTATABLE CRAWLER UNIT FOR SELECTIVE LONGITUDINAL OR SIDEWISE MOVEMENT Filed Oct. 18, 1961 5 Sheets-Sheet 3 s? &:

BY I

ATTORNEYS June 26, 1962 R TERRELL I 3,040,829

ROTATABLE CEAWLER UNIT FOR SELECTIVE LONGITUDINAL OR SIDEWISE MOVEMENT Filed Oct. 18, 1961 5 Sheets-Sheet 4 INVENTQR [Mari]. 1. 11?

ATTORNEYS June 26, 1962 Filed Oct. 18, 1961 R D. TERRELL ROTATABLE CEAWLER UNIT FOR SELECTIVE LONGITUDINAL OR SIDEWISE MOVEMENT 5 Sheets-Sheet 5 Q I 59 I 6 Z N 72 INVENTOR [Maria [h re/I ATTORNEYS United States This invention relates to crawler units for use as propulsion means for heavy equipment. It is particularly adapted for use with mining machinery of the automatic type which is sumped into the mine face to be cut, and conveys to the rear the material broken down.

It has become customary in mining, and coal mining particularly, to employ automatic machinery which will move into a mine tunnel under its own power and to a position in front of the face being worked. The machine usually carries a cutting head of some kind, which will cut, or bore, into the coal face and break down the coal in lump form. The machines normally have conveying means to transport the coal broken down to the rear of the machine for removal from the mine. After the cutter head has been moved into the face a maximum practical depth, it is retracted and the machine moved to the side so that another cut can be made adjacent the first one. This procedure is repeated until the full width of the tunnel has been traversed. The equipment is extremely heavy and awkward to move. It is normally provided with nonsteerable wheels, or endless tread crawlers. In order to move the machines laterally of the tunnel, jacks and cables have been used to actually drag the machine to the side. This requires the services of several men and is an unwieldy operation at best.

Machines have been proposed for continuous mining operations, wherein the cutter head is capable of cutting into the coal face a predetermined depth, rotating 90 to bring its axis parallel to the face and then cutting across the full width of the tunnel. While this provides a very eflicient breakdown of coal and rapid mining, particularly in shallow vein mining, movement of the machine across the mine face has presented a major problem.

The primary object of the present invention is to provide a crawler unit which is capable of powered operation to provide selective ground-traversing movement along two paths which are normal to one another.

Another object is to provide crawler type propulsion units mounted to permit normal movement of the endless treads of the units for forward and backward movement of the vehicle which they carry, but rotation of the entire units about longitudinal axes to provide sidewise movement of the vehicle.

A further object of the invention is to provide propulsion units of the above-described type which may achieve the two-ground-traversing movements through power from a single source and through a single drive shaft.

Other objects of the invention will become apparent from the following description of one practical embodiment thereof, when taken in conjunction with the drawings which accompany, and form part of, this specification.

In the drawings:

FIGURE 1 is a top plan view of a mining machine having a crawler unit running gear incorporating the features of the present invention;

FIGURE 2 is a side view of the machine;

FIGURE 3 is a horizontal section through one of the crawler units and its frame mounting, taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a longitudinal, vertical section taken on the line 44 of FIGURE 3;

atent 3,ll40,829 C6 Patented June 26, 1962 FIGURE 5 is a view of the drive end of the unit showing the unit in side elevation and the machine frame structure in section;

FIGURE 6 is a transverse section through the unit, taken on the line 66 of FIGURE 5;

FIGURE 7 is a view similar to FIGURE 6 but with the unit rotated from the position shown in FIG-v URE 6;

FIGURE 8 is a vertical, transverse section taken on the line 3-8 of FIGURE 5, illustrating the mounting for the crawler unit drive and actuator;

FIGURE 9 is a horizontal section taken on the line 9-9 of FIGURE 5, showing the drive for the unit;

FIGURE 10 is a transverse section taken on the line Id-ll) of FIGURE 5, showing the clutch elements and locking assembly;

FIGURE 11 is a section taken on the line 11-11 of FIGURE 5; and

FIGURE 12 is a fragmentary section taken on the line 12-42 of FIGURE 10 with the clutch elements engaged and the locking bar in release position.

In general, the invention is concerned with improved propulsion devices of the crawler type, capable of for.- ward and backward movement, or to one side or the other under control of an operator. The units have the usual endless treads for forward and backward movement; and each is capable of being bodily rotated about a longitudinal axis to provide transverse motion.

Referring to the drawings in detail, there is shown a mining machine I which includes a crawler unit 2 that carries a cutter head, and a sumping and conveyor frame 3 movable longitudinally relative to the crawler unit. Frame 3 can move forwardly to sump the cutter-head into the face being mined, or retracted to a carrying position on the crawler unit for transportation. The mining machine here shown is for purposes of illustration only, and is merely illustrative of any equipment carried by crawler unit 2.

The crawler unit has a body 4 of generally inverted u-shapfi, defining a central well 5, for receiving the frame 3, and a pair of longitudinally extending parallel legs 6. The body may be of any appropriate construction, and for purposes of disclosure, it is shown as comprising transversely spaced, parallel side plates 7 joined by a top plate 8 which over-lies, and projects transversely beyond the side plates 7. Side covers 9 and bottoms 10 complete the boxings for the legs 6. For clarity and simplification of disclosure, no further details of body construction are shown. Each leg 6 is recessed along its bottom and outside edges, as at 11, to accommodate crawler track assemblies 12.

The assemblies 12 are identical and only one will be described. The assembly includes an endless track 13 and a track mounting frame :14, having longitudinally extending end trunnions 15 and 16 which are journalled in transverse bearing plates 17 and 18, respectively, carried by the crawler body legs, forming partitions therein, and providing end walls for the recesses 11.

The mounting frame is constructed from a front bearing block casting 19, which includes the front trunnion 15 as a part thereof (see FIGURE 3), a rear bearing block casting 20, which includes the rear trunnion 16, a center casting 21, extending between the front and rear castings, and side bar castings 22, which overlie the center, front and rear castings on either side and are bolted to them by means of bolts 23 (see FIGURES 5, 6 and 7), to hold the several castings in assembled relation to complete the frame. The front and rear bearing block castings serve as fillers between the ends of the side bars and as bases from which the trunnions emanate to provide means for mounting the entire frame for rotation about a longitudinal axis formed as a continuation of the aligned axes of the trunnions.

The center casting is shown as having a pair of transversely spaced, longitudinally extending rails 24, tied together by horizontal webs *25, and bearing bosses 26 which mount the shafts 27 of trackbearing rollers 28. The shafts have their ends seated in bosses 29 formed on the inner faces of the side bars 22. Near their front ends, the side rails are apertured, as at 30 to receive bearings 31 to journal a sprocket drive shaft 32 for the crawler track. Shaft 32 carries a track drive sprocket 3 3 at its center, between the side rails, and small sprockets 34 at each end. Chains 35 over sprockets 34 and sprockets 36 on opposite ends of stub drive shaft 37, journalled in the front bearing block 19, drive the sprocket drive shaft 32, as will be described. At the rear, rails 24 have elongated openings 38 to slidably receive shaft 39 which carries the track idler sprocket 40. The shaft is mounted in adjusting blocks 41, slidable in guides 4-2 to serve as take-up means to keep the chain taut. Adjusting bolts 43 pass through the ends of the side bar castings 22 and are threaded into the take-up blocks 41 in more or less conventional fashion. The arrangement of the track and 7 its mounting is conventional.

. Side bars 22 are quite thick, and have their outer faces contoured to provide a substantially continuous earthengaging surface when the crawler assemblies are rotated about their trunnions. The major portions of the outer surfaces of the side bars are cylindrical curves forming part of a skeleton cylinder to which the tread surfaces of the crawler track are tangent as they move along the top and bottom flights of the crawler track path. This cylinder is represented by the broken circle a shown in FIGURE 6. The outer side edges of the crawler tread and longitudinal ribs 44 formed on the side bars project from the geometric center of the crawler assembly such distances that they define points of a larger circle than the circle a, and form cleats to dig into the earth of a mine floor as the crawler assemblies are rotated, so that a positive hold is obtained upon the ground to prevent slipping. The 'cleat circle is shown at b in FIGURE 6. The cross-sectional contour of the assembly may vary from that shown, but good results have been obtained where the overall shape is generally cylindrical and offset lugs, or cleats, are provided.

The tracks of the crawler assemblies are caused to move, and the assemblies are rotated about their trunnions by means of a principal drive shaft 45 which is coaxial with the axis of rotation of the assembly. The shaft is in two sections, joined 'by a coupling 46. The drive endsection of the shaft is connected to a reducer 47, supported by a bracket 48, secured to the crawler unit top plate 8. The reducer is driven by a hydraulic motor 49. The driven end section of the shaft is journalled in the front bearing block casting 19 in bearings 50. The extreme end of this section carries a bevel gear 51 which is in mesh with a bevel gear 52 on shaft 37. Thus, rotation of the principal drive shaft 45 will cause rotation of shaft 37 and, through chains 35, rotation of the crawler track sprocket shaft 32 and movement of the track. The direction of rotation of the shaft 45, of course, will determine the direction of movement of the track and of the crawler unit.

' In order to accomplish the above described movement, it is necessary that the crawler track assembly be held against rotation on the trunnions 15 and 16 To do this, a coupling plate 53 is bolted to the end of the fiont trunnion 15, on the opposite side of bearing plate 17 from the crawler mounting frame 14. The face of the trunnion is notched, as at 54, to seat. lugs 55 formed on the coupling plate, to hold the trunnion and coupling plate against relative rotative movement. Plate 53 has a looking notch 56 in its periphery to receive locking key 57. Key 57 is mounted for sliding movement within a keyway 58 formed in the bearing plate 17. When the key is positioned so that it is seated partly within the keyway and partly within the locking notch 56, the coupling plate will be held against movement and thus prevent rotation of the crawler track assembly. The notch 56 is so located that the crawler assembly will be locked with the crawler tread in ground-engaging position, as shown in FIGURES 5 and 6.

The locking key has a locking tongue 59 and a mounting arm 60. The tongue projects downwardly for engagement in the notch 56, and the mounting arm extends above the periphery of the coupling plate. The notchentering edge of the tongue is tapered for easy entry into the notch, and is recessed, as at 61, to receive a roller 62 for rolling engagement with the face of the coupling plate when the locking key is urged toward notch-engaging position and the notch is not in key-receiving position. The roller is mounted upon a shaft 63 fixed within the locking key.

The mounting arm of the locking key is secured to a clutch shifting fork 64, carried by an actuating shaft 65 having one end slidable in an opening 66 in plate 17 and its other end coupled to the piston shaft 67 of a hydraulic actuator cylinder 68. Cylinder 68 is suspended from the top plate '8 of the crawler unit by means of mounting members 69. Operation of the cylinder will cause axial movement of actuator shaft 65 and shifting of the locking key to and from notch-engaging position relative to the coupling plate.

Shifting fork 64 is operably connected to a movable clutch element 70 which is slidably mounted on a splined section 71 of the drive shaft '45. Clutch element 70 has a plurality of clutch lugs 72 for clutching engagement in companion recesses 73 in the face of coupling plate 53. As the clutch element 70 and the locking tongue 59 of key 57 are positioned on opposite sides of the coupling plate, movement of the shifting fork in one direction (to the right as viewed in FIGURE 5 will cause simultaneous seating of the locking tongue in notch 56 of the coupling plate and disengagement of the clutch element 70 from the coupling plate. Movement in the opposite direction will move the locking tongue from the coupling plate notch and engage the clutching element and coupling plate.

It will be obvious that when the locking key is in engagement with the notch in the coupling plate the crawler track assembly will be held against rotation, and operation of the drive shaft 45 will cause the crawler track to advance along the frame and move the machine forwardly, or backwardly, as desired. When the locking key is removed from the notch and the clutch element engaged with the coupling plate, the crawler track frame will be coupled directly with drive shaft 45 and rotate with it. This will cause the crawler track units to function as drive rollers to move the crawler unit transversely to one side or the other. As soon as the crawler track I frame is coupled to the drive shaft 45, relative movement between the shaft and frame ceases and, thus, the drive of the crawler track automatically stops. When it is desired to stop sidewise movement of the machine, cylinder 68 is operated to move the locking key into notch-engaging position. As the clutch element cannot disengage until the key moves into the notch, the coupling plate will continue to rotate with the locking key roller in contact with it if the notch is out of alignment with the key position when the cylinder is operated. With movement of the key into the notch, the clutch element releases and the crawler track assembly is locked for conventional operation. As soon as the frame is held against rotation the drive to the crawler track will be re-established automatically.

It will be found frequently that when the machine is moved transversely a desired position will be reached when the crawler tracks are not in ground-engaging position. To continue rotation of the crawler track assemblies until the tracks contacted the ground would result in further movement of the machine. In order to provide for such circumstances, the crawler unit is provided with four hydraulic jacks 74, one at each corner of the unit. These will be connected to a suitable supply of fluid under pressure and when operated will lift the crawler unit from the ground. When the unit is raised, drive shaft 45 may be started to rotate the crawler track assembly until the locking key moves into the coupling plate notch. When the assembly is locked in position to allow for normal operation of the tracks, the jacks 74 may be operated to lower the crawler unit to rest upon the tracks.

It will be obvious that the hydraulic motors 49 and the hydraulic control cylinders 68 Will be connected to a suitable supply of operating fluid carried by the machine. The several mechanisms will be controlled by levers 75 mounted for convenient manipulation by an operator. The fluid supply and the connections from the supply to the controls and the hydraulic units have not been shown as such structure is well known in the art.

When a mining machine mounted upon the disclosed crawler unit is to be used, it is run into the mine by operation of the crawler track in normal manner. When the mining position is reached, and a cut of desired depth has been made, the frame will be retracted and lifted, and cylinders 68 actuated to slide locking keys 57 from the notches of the coupling plates 53 and couple the clutch elements to the coupling plates. Operation of motors 4'9 will revolve the crawler track assemblies and shift the machine laterally the desired amount. When the machine reaches the desired location, motors 49 are stopped, jacks 74 actuated to lift the machine, cylinders 68 made operative to move the locking keys into engagement with the coupling plates, and motors 49 restarted to rotate the track assemblies until the coupling plate notches are in alignment with the locking keys. At this point, rotation of the trailer assemblies will stop with the bottom flight of the track in ground-engaging position. The anchors may be engaged again and the frame advanced for a new cut.

While one practical embodiment of the invention has been disclosed, it will be understood that the details of construction shown and described are merely by way of illustration and the invention may take other forms with in the scope of the appended claims.

What is claimed is:

l. A crawler assembly comprising, a body, an elongated frame, an endless track mounted on the frame for movement longitudinally of the frame along at least one side of the frame, bearing members in the body mounting the frame for rotation about the central longitudinal axis of the frame, means to advance the endless track along the frame, means to rotate the frame within the bearing members, and means to selectively render operative the means to advance the track and the means to rotate the frame.

2. A crawler assembly as claimed in claim 1, wherein there is means to lock the frame against rotation.

3. A crawler assembly as claimed in claim 1, wherein the frame and mounted track form a unit which is generally circular in transverse cross-section.

4. A crawler assembly comprising, a body, an elongated frame, track sprockets mounted in the frame intermediate the ends of the frame spaced apart longitudinally of the frame, an endless track trained over the sprockets and movable along opposite sides of the frame, trunnions extending in opposite directions from the ends of the frame in axial alignment with each other and the central longitudinal axis of the frame, bearing members in the body to rotatably mount the trunnions, releasable means to lock the frame against rotative movement, means operative when the frame is locked against rotation to drive one of the sprockets to advance the endless track, and means operative when the lock means is released to rotate the frame Within the bearing, members.

5. A crawler assembly as claimed in claim 4, wherein the frame and mounted track form a unit of generally circular transverse cross-section.

6. A crawler assembly as claimed in claim 4, wherein 6 the lock means isope'ra'tive only when the' assembly is oriented to position the endless track at the top and bottom of the frame.

7. A crawler assembly comprising, a body, an elongated frame, track sprockets mounted in the frame intermediate the ends of the frame spaced apart longitudinally of the frame, an endless track trained over the sprockets and movable along opposite sides of the frame, trunnions extending in opposite directions from the ends of the frame in axial alignment with each other and the central longitudinal axis of the frame, bearing members in the body to rotatably mount the trunnions, whereby the frame may rotate about its central longitudinal axis, means to rotate the frame including a shiftable clutch member, means to drive one of the sprockets to advance the endless track, means to lock the frame against rotation, and control means connected to the lock means and to the clutch member to operate the lock means and shift the clutch member simultaneously in opposite phase to move the lock means to a locking position and the clutch member to de-clutched position and to move the lock means to a lock release position and the clutch member to clutch position.

8. A crawler assembly as claimed in claim 7, wherein the locking means includes a locking key, and one bearing member and the frame have keyways for simultaneous engagement by the locking key to lock the frame against rotative movement relative to the bearing member.

9. A crawler assembly as claimed in claim 8, wherein the respective keyways are located so that when the keyways are in locking alignment the endless track is in ground-engaging position.

10. A crawler assembly comprising, a body, an elongated frame, track .sprockets mounted in the frame intermediate the ends of the frame spaced apart longitudinally of the frame, an endless track trained over the sprockets and movable along opposite sides of the frame, trunnions extending in opposite directions from the ends of the frame in axial alignment with each other and the central longitudinal axis of the frame, bearing members in the body to rotatably mount the trunnions, whereby the frame may rotate about its central longitudinal axis, a drive shaft extending axially through one of the trunnions and rotatably mounted therein, means interconnecting the drive shaft and one of the sprockets to drive the connected sprocket to advance the endless track, clutch means carried by the drive shaft for rotation therewith and slidable therealong, a coupling plate fixed to the end of the trunnion through which the drive shaft extends and for clutching engagement with the clutch means to rotate the frame with the drive shaft, a locking key slidably mounted in one bearing member, said coupling plate having a keyway therein to receive the looking key to hold the plate and frame against rotation, control means connected to the locking key and clutch means to simultaneously move the locking key out of the plate keyway and the clutch means into clutching engagement with the coupling plate to institute rotation of the frame and cause cessation of track movement, and to simultaneously move the locking key into the plate keyway and the clutch means out of engagement with the coupling plate to hold the frame against rotation and re-establish movement of the endless track.

11. A crawler assembly as claimed in claim 10 wherein, the position of the locking key and the keyway in the coupling plate are so oriented relative to the track position on the frame that the key will engage the keyway to hold the frame against rotation only when the track is in ground-engaging position.

12. A crawler assembly as claimed in claim 11 wherein, jacks are carried by the body to lift the assembly from the ground.

13. A crawler unit comprising, a body, a pair of crawler assemblies mounted in spaced parallel relation on the body, each crawler assembly comprising, an elongated frame, track sprockets mounted in the frame intermediate the ends of the frame spaced apart longitudinally of the frame, an endless track trained over the sprockets and movable alongopposite sides of the frame, trunnions extending in opposite directions from the ends of the frame in axial alignment with each other and the central longitudinal axis of the frame, bearing members in the body to rotatably mount the trunnions, whereby the frame may rotate about its central longitudinal axis, means to rotate the frame including a shiftable clutch member, means to drive one of the sprockets to advance the endless track, means to lock the frame against rotation, and control means connected to the lock means and to the clutch member to operate the lock means and shift the clutch member simultaneously in opposite phase to move the lock means to a locking position and the clutch member to de-clutched position and to move the lock means to a lock release position and the clutch member to clutch position.

References Cited in the file of this patent UNITED STATES PATENTS Aghnides Mar. 20, 1945 Bonma-rtini June 19, 1956 Wagner Sept. 12, 1961 FOREIGN PATENTS France May 20, 1935 

